Refrigerating apparatus



Oct. 30, 1934. p ILL IE 1,978,520

REFRIGERAT ING APPARATUS Filed May 23, 1951 INVENTOR 6M ATTOR EYS Patented Oct. 30, 1934 OFFICE Y7 REFRIGERATING APPARATUS Henry E. Willsie, New York, N. Y., assignmto The Union Trust Company, Cleveland, Ohio, a corporation of Ohio Application May 23, 1931, Serial No. 539,509

i Claims.

The invention disclosed in this case rela I generally to refrigerating apparatus, and specifically to a means for returning any boiler liquor going over to the evaporator from the 8 still and preventing the undesirable accumulaing period, for example, and the other end'is tion of this liquor in the evaporator.

Heretofore many seals, including valves and the like, have been used for controlling the return, at some time in the cycle, of undesirable boiler liquor from the evaporator, but most of these devices have been unreliable for one reason or another so that no certain operation of the entire apparatus is possible under the various conditions to which it is subjected.

The object of the present invention therefore is to provide a boiler liquor drain connected with the evaporator for returning such liquor,

preferably once in every complete cycle, and to arrange'the device in such a way that it is certain in operation under all conditions.

Specifically, the device is in the form of a drain connected to substantially the bottom of the evaporator and extending upward above the maximum level of the refrigerant therein and thence to the boiler, the arrangement being such that the evaporator end of the drain is sealed by the boiler liquor to be drained and refrigerant therein at the beginning of the heatsealed at this same time, for example, by the liquor in the still, there being trapped in this drain pipe at this time, between the two liquid seals, by the normal operation of the device, a gaseous medium which is capable of compression.

Upon the heating of the still and a production of pressure throughout the apparatus, this pressure is made effective not only upon any liquor in the evaporator, but also upon the liquor in the boiler, producing the compression of this volume of gas in the drainbetween the two seals and causing the gaseous medium to compress and also causing the liquid column of the evaporator seal to pass up above the liquid level in the evaporator over the top and fiow down the drain, trickle through the gaseous medium there in, and find its Way to the still. Continuance of this operation will ultimately drain the evapora-' tor of all its liquid. This, condition however can only exist so long as both ends of the drain are sealed and hence the lower entrance to the drain, or that connected with the still, should be at such a level with respect to the still boiler liquor that it is sealed when the drain is to take proper cycle, for instance the heating or gassing cycle, may properly take place to deposit useful refrigerant in the evaporator and condenser for use later in the refrigerating cycle when the heat is turned oil. While it is believed that the drain just disclosed may operate when its still end is connected with the still just below and near the normal liquid level therein at the end of the absorption period, it may be connected to any other point where it is sealed at one time and is exposed for drain to break the seal at another. Such a point, for example, may be in a conduit constituting the gas return to the still during the absorption period so that none of the useful refrigerant is drained back due to any condition which may be set up in the apparatus.

The invention may be briefly summarized as being that which is disclosed in the following description, drawing and claims.

Referring to the drawing, the figure shows in more or less diagrammatic form a refrigerating circuit embodying the invention.

In the drawing, 1 represents a still of the usual form. This still may be provided with a cooling loop 2 preferably extending down below the still and in some instances projecting into cooling liquid in a tank 3. Projecting from the top of the still is the usual hairpin loop 4 rising above the still and returning to the bottom of a trap 5, which is a closed casing above the still. Rising from the top of this trap is a gas pipe 6 leading to the rectifier and extending to the tonof the evaporator, indicated at '7, Extending from the top of this evaporator is a condenser pipe 8 leading to a condenser 9, which may be located in the tank 3. Extending from the gas space of the trap 5 is a gas return'pipe 10, preferably connected, as at 11, to one leg of the loop 2.

Connected to the bottom of the evaporator is a drain pipe 12, which extends upwardly in a loop 13 to a point slightly above the desired level of liquid refrigerant in the evaporator and thence down and connected preferably in the gas return pipe 10 at the point 14, which should be below the normal level of the liquid in thestill end of the evaporator. The location of this connection should be always below the level of the liquid in the still, as stated, but its position may be varied so long as it returns, as will appear, the undesirable boiler liquor and does not return useful refrigerant.

While, as above, it is stated that the drain pipe may enter the still or other part just below the normal maximum level of the boiler liquor in the still at the end of the absorption period, in

s in the evaporator.

some arrangements it may be above this level where the pressure in the circuit causes a rise of boiler liquor above the boiler end of the drain at, for example, the beginning of the heating cycle. In the specific arrangement shown, it enters the gas return pipe from the liquid seal or trap 5, and in this case it is obvious that the boiler liquor will rise in this gas return pipe, as the pressure builds, up even above the level of the liquid in the still. Hence, the still end of the drain pipe could well be arranged above the normal still liquid level at the end of the absorption period. It is obvious, that since the return gas pipe is free from liquid during the absorption period, that thestill end of the drain pipe 12 is uncovered and therefore there can be no further draining of the evaporator during the absorption period.

In operation, assuming that the heat is just coming on after a completed absorption period and. that the still liquor stands at the point indicated in dotted lines in the drawing, as the pressure rises throughout the plant, it is of course efiective through the conduits 4 and 6 upon the top of any liquor which may be present It is likewiseeifective upon the boiler liquor itself and since both the evaporator and the still ends of the drain pipe are sealed with liquor, and since the volume of gaseous medium is present in the drain pipe due to the fact that this pipe was previously drained of any liquor during the absorption period, then this pressure, due to the heat, causes a compres-- sion of the gaseous medium in the drain pipe and a consequent movement not only of the still liquor up into this drain pipe at one end, but evaporator liquorup through the riser of this drain pipe at the evaporator. This continues as the pressure builds up until finally the seal at the evaporator end of the drain tube causes the evaporator liquor to travel up over the loop 13 and thence through the tube to the gas return pipe where it may pass into the still through this gas return pipe. The discharge through this drain in this way continues until'the liquor in the evaporator is exhausted and the seal at this end of the drain pipe is broken. By this time substantially all of the undesirable still liquor and indeed possibly a small amount of refrigerant is returned to the still. The continued heating of the still then produces the normal heating cycle with the consequent collection of the liquid refrigerant in the condenser ready for return to the evaporator uponthe cessation of heat and the beginning of the refrigerating cycle.

There can be no drain in any appreciable quantity of useful refrigerantfrom the evaporator during the absorption period because the gas returns through the gas return pipe 10 past the mouth of the drain pipe breaking its seal and obviously doing away with any possibility of a compressible medium being trapped between seals in the drain pipe.

The connection of the drain to the gas return pipe is indicated as located somewhere below the normal level of absorbent in the still, but its position may be varied to suit conditions and could well be somewhat above this level, due to the fact that absorbent will rise in the gas return pipe toward the space in the trap at the beginning of the heating period.

Having described my invention, I claim:

1. In an absorption cycle refrigerating apparatus, a still, evaporator and condenser connected in operative series, a liquid trap intelposed in the circuit between the still and evaporator, a gas return line from said trap to the lower portion of said still, and a drain from said evaporator to said still, the lower end of the drain being connected to said gas return line at a point substantially level with the normal level of the liquid in the still.

2. In an absorption cycle refrigerating apparatus, a still, evaporator and condenser connected in operative circuit, a liquid trap in the circuit between the still and the evaporator, a gas returnline connecting the trap and still below the normal liquid level maintained therein, and an independent drain line leading from the 'bottom portion of the evaporator to the gas return line.

3. In an absorption type refrigerating apparatus including a still-absorber and evaporator connected through an intermediate liquid trap, a condenser in circuit with said evaporator and positioned below said still, a gas return connecting said trap and the lower portion of said still, a drain leading from said evaporator to said gas return, the lower portion of the drain being free from liquid during the absorption period of the refrigerating cycle.

4. In an absorption type refrigerating apparatus including a still-absorber and an elevated evaporator connected through the medium of a liquid trap, a gas return connecting said trap and the lower portion of said still-absorber, and a drain pipe connecting the evaporator through a seal to the gas return line at a point above the normal liquid level of the still-absorber.

5. In an absorption cycle refrigerating apparatus, a still-absorber, evaporator and condenser connected in operative series, a closed loop depending from said still-absorber, a gas return leading from said evaporator to said closed loop, and a drain leading from said evaporator and connected tosaid gas return at a point substantially at the normal liquid level of said still.

HENRY E. WILLSIE. 

